[Lua] Suppress some diagnostics and also recommend suppressing certain diagnostics globally

data/lua/core/map.lua

@@ -274,6 +274,7 @@ if wesnoth.kernel_type() == "Game Lua Kernel" then
 		---@type location
 		local loc, n = wesnoth.map.read_location(x, y)
 		if n == 0 then error('Missing or invalid coordinate') end
+		---@diagnostic disable-next-line: return-type-mismatch
 		return setmetatable({x = loc.x, y = loc.y}, hex_mt)
 	end
 
@@ -282,7 +283,7 @@ if wesnoth.kernel_type() == "Game Lua Kernel" then
 	---@param cfg WML
 	---@param ref_unit? unit
 	---@return terrain_hex[]
-	function wesnoth.map.find(cfg, ref_unit)
+	function wesnoth.map.find(cfg, ref_unit) ---@diagnostic disable-line: duplicate-set-field
 		local hexes = find_locations(cfg, ref_unit)
 		for i = 1, #hexes do
 			hexes[i] = wesnoth.map.get(hexes[i][1], hexes[i][2])

data/lua/core/wml.lua

@@ -1,4 +1,5 @@
 --[========[Config Manipulation Functions]========]
+---@diagnostic disable: deprecated
 print("Loading WML module...")
 
 local function ensure_config(cfg)

utils/emmylua/README.md

@@ -6,6 +6,8 @@ To enable in Visual Studio Code, install [this Lua plugin](https://marketplace.v
 
 ```json
 "Lua.runtime.version": "Lua 5.4",
+"Lua.type.weakNilCheck": true,
+"Lua.type.weakUnionCheck": true,
 "Lua.workspace.library": [
   "./utils/emmylua"
 ],